JP7171287B2 - Shutter device and imaging device - Google Patents

Description

The present invention relates to a shutter device.

2. Description of the Related Art Conventionally, an imaging apparatus that performs an imaging operation using both a focal plane shutter (mechanical shutter) and an electronic shutter has been proposed for cost reduction. This image pickup apparatus starts an exposure operation using an electronic shutter of an image pickup device, and completes the exposure operation by running a blade group of a mechanical shutter. In addition, in order to prevent the surface of the imaging sensor from being exposed to light while exposure data is being transferred from the imaging sensor, it is necessary for this imaging apparatus to maintain a state in which the blade group covers the surface of the imaging sensor after exposure. be. For this reason, unlike an imaging apparatus having a mechanical shutter of two sets of blades, it is necessary to wait for transfer and then drive the blades to prepare for photographing.

In order to shorten the drive time of the blade group, for example, Japanese Patent Application Laid-Open No. 2002-200002 discloses a blade lever with a biasing spring that biases the blade group in the photographing preparation direction, and a blade lever that is attached in the direction in which the blade lever travels during the exposure operation. A shutter device is disclosed that includes a drive lever with a main spring biasing it. In this shutter device, only the drive lever is charged in parallel with the transfer of the exposure data, and the blade lever is driven after the transfer of the exposure data.

Japanese Unexamined Patent Application Publication No. 2012-113112

However, in the shutter mechanism disclosed in Patent Document 1, the main spring must charge the biasing spring of the blade lever. In addition, since the charge angle of the blade lever is large, the cam follower of the blade lever once approaches the rotation center of the cam and then moves away from it during charging. Therefore, it is difficult to arbitrarily create a cam diagram, and it is difficult to smooth the load. As a result, a high-torque motor is required to charge the main spring, which increases the size and cost of the shutter device.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to reduce the size and cost of a shutter device.

The shutter device of the present invention for achieving the above object comprises a group of shutter blades reciprocally movable between a closed state for closing an opening and an open state for opening the opening; 1 driving means, a second driving means for driving the first driving means in a first direction in which the shutter blade group closes the opening, and a first driving means for urging the first driving means. biasing means, second biasing means for biasing the second driving means in the first direction, third driving means for driving the first driving means, and the third driving means a first power transmission means for transmitting the power of the means to the first driving means; and a fourth driving means for driving the second driving means in a second direction in which the group of shutter blades opens the opening. and second power transmission means for transmitting the power of the fourth drive means to the second drive means, wherein the fourth drive means has a distance from the center of rotation of the fourth drive means. The second drive means is driven through the second power transmission means configured such that the contact point with the drive means of No. 4 is shorter than the contact point with the second drive means .

Other objects and features of the invention are described in the following embodiments.

According to the present invention, it is possible to reduce the size and cost of the shutter device.

1 is a configuration diagram of an image capturing apparatus provided with a shutter device according to this embodiment; FIG. 2 is an exploded perspective view of the shutter device according to the embodiment; FIG. FIG. 3 is a partially enlarged view of the drive unit of the shutter device according to the embodiment, viewed from the front (lens side); 4 is a timing chart showing the operation of the shutter device according to the embodiment; FIG. 4 is an explanatory diagram from a standby phase to a photographing phase of the shutter driving section in the embodiment; FIG. 5 is an explanatory diagram from a charge phase to a blade return drive phase of the shutter drive section in the embodiment;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

First, with reference to FIG. 1, the configuration of an imaging apparatus having a shutter device according to this embodiment will be described. FIG. 1 is a configuration diagram of an imaging device (digital single-lens reflex camera) 10. As shown in FIG. The imaging device 10 is configured by including a camera body 1 and an interchangeable lens (lens device) 2 that can be attached to and detached from the camera body 1 . However, the present invention is not limited to this, and can also be applied to an imaging device in which a camera body and a lens device are integrated.

The camera body 1 has a focus detection unit 3 , an optical finder unit 4 , a main mirror 5 , a sub-mirror 6 , a shutter device (focal plane shutter) 100 and an image sensor (image sensor) 7 . A light beam L transmitted through the interchangeable lens 2 is incident on the main mirror 5 of the camera body 1 . The main mirror 5 is a half mirror that can move back and forth within the imaging optical path. A light beam L1 reflected by the main mirror 5 is guided to the optical finder unit 4. - 特許庁On the other hand, the light flux L2 transmitted through the main mirror 5 is reflected downward by the submirror 6 and guided to the focus detection unit 3. FIG. The sub-mirror 6 is rotatably held by the main mirror 5 and advances and retreats in the photographing optical path at the same time as the main mirror 5 .

A shutter device 100 is provided behind the sub-mirror 6 . An imaging sensor 7 is provided behind the shutter device 100 . The imaging sensor 7 photoelectrically converts an optical image formed via the interchangeable lens (imaging optical system) 2 and outputs image data. When the main mirror 5 and the sub-mirror 6 are retracted from the photographing optical path, the light flux L that has passed through the interchangeable lens 2 passes through the aperture (opening) of the shutter device 100 and enters the imaging sensor 7 . During photographing, the amount of exposure is controlled by resetting the image sensor 7 and changing the opening size of the aperture of the shutter blades of the shutter device 100 .

Next, the configuration and operation of the shutter device 100 will be described with reference to FIGS. 2 and 3. FIG. FIG. 2 is an exploded perspective view of the shutter device 100. FIG. FIG. 3 is a partially enlarged view of the drive unit of the shutter device 100 as seen from the front (lens side). 3(A) omits some parts such as the shutter base plate 120, and FIG. 3(B) omits some parts from FIG. 3(A).

A cover plate 121 is attached to the shutter base plate 120 at a predetermined interval. Apertures (openings) 120a and 121a having mutually similar shapes are formed in the shutter base plate 120 and the cover plate 121, respectively. A rectangular exposure opening formed by superimposing two apertures 120 a and 121 a defines a light beam passing through the shutter device 100 . A blade chamber is formed between the shutter base plate 120 and the cover plate 121 . A shutter blade group 101 comprising light shielding blades and blade arms is arranged inside the blade chamber.

The shutter blade group 101 can reciprocate between a closed state (overlapping state) in which the apertures (openings) 120a and 121a are closed and an open state (unfolded state) in which the openings are opened. A blade lever 102 is connected to the shutter blade group 101 . The blade lever 102 is rotatable in a first direction (clockwise rotation direction, unfolding direction) in which the shutter blade group 101 closes the opening and in a second direction (counterclockwise rotation direction, overlapping direction) in which the opening is opened.

The shutter base plate 120 is provided with shafts 120b, 120c, 120d, 120e, and 120f. A shaft (not shown) provided coaxially with the shaft 120b is provided on the back side of the shutter base plate 120, and the shutter blade group 101 is drivably attached to this shaft. A blade lever (first driving means) 102 and a driving lever (second driving means) 103 are rotatably attached to the shaft 120b. The blade lever 102 has a shaft 102c. The shaft 102c is engaged with the blade arm of the shutter blade group 101. As shown in FIG. That is, the blade lever 102 is connected with the shutter blade group 101 . Accordingly, the shutter blade group 101 is expanded or overlapped with the rotation of the blade lever 102, thereby controlling the luminous flux passing through the apertures 120a and 121a.

A blade biasing spring (first biasing means) 106 is attached to the shutter blade group 101 . The biasing force of the blade biasing spring 106 in the right rotation direction as viewed from the front enables the shutter blade group 101 to maintain the unfolded state. An armature 110 is attached to the blade lever 102 with some play. The yoke 119 is attached to a cover member (not shown) at a position where it reliably contacts the armature 110 when the shutter blade group 101 is superimposed. That is, the blade lever 102 overcharges the armature 110 with respect to the yoke 119 when the shutter blade group 101 is superimposed. Also, by energizing a coil (electromagnet) 109 wound around the yoke 119, the yoke 119 can attract and hold the armature 110 by magnetic force.

The drive lever 103 is urged in the right rotation direction in a front view by a main spring (second urging means) 107 . The blade lever 102 has a surface 102a. The drive lever 103 has a contact portion 103 a that contacts the surface 102 a of the blade lever 102 by being biased by the main spring 107 . The drive lever 103 is urged by the main spring 107 to drive the shutter blade group 101 in the right rotation direction (deployment direction) together with the blade lever 102 in the front view.

A blade driving cam (third driving means) 104 and a charge cam (fourth driving means) 105 are rotatably provided on the shaft 120c of the shutter base plate 120. As shown in FIG. A blade drive transmission lever (first power transmission means) 113 and a charge transmission lever (second power transmission means) 114 are rotatably provided on the shaft 120d of the shutter base plate 120 . The blade drive transmission lever 113 is biased by a spring (third biasing means) 116 in a counterclockwise rotation direction (a direction to contact the blade drive cam 104) in the front view. The charge transmission lever 114 is urged by a spring 118 in a counterclockwise rotation direction (a direction in which it contacts the charge cam 105) in the front view.

The blade drive cam 104 and the charge cam 105 are integrally molded so as to rotate together, or are attached to each other so as to rotate together, and are connected to the motor via a gear train (not shown). Power from 108 rotates left in the front view. The blade drive cam 104 has a cam surface 104a. The cam surface 104 a contacts the cam follower portion 113 a of the blade drive transmission lever 113 to drive the blade drive transmission lever 113 . The blade drive transmission lever 113 has a cam surface 113b. Cam surface 113 b contacts cam follower portion 102 b of blade lever 102 to drive blade lever 102 . The charge cam 105 has a cam surface 105a. The cam surface 105 a contacts the cam follower portion 114 a of the charge transmission lever 114 to drive the charge transmission lever 114 . The charge transmission lever 114 has a cam surface 114b. The cam surface 114 b contacts the cam follower portion 103 b of the drive lever 103 to drive the drive lever 103 . That is, the blade lever 102 is driven by the rotation of the blade drive transmission lever 113 in contact with the rotation of the blade drive cam 104 . Also, the drive lever 103 is driven by the rotation of the charge transmission lever 114 in contact with the rotation of the charge cam 105 .

The blade drive cam 104 has a cam top surface 104b concentric with the center of rotation. The cam top surface 104b is provided so as to be continuous with the cam surface 104a. The charge cam 105 has a cam top surface 105b concentric with the rotation center. The cam top surface 105b is provided so as to be continuous with the cam surface 105a. The blade drive transmission lever 113 has a cam top surface 113c concentric with the rotation center. The cam top surface 113c is provided so as to be continuous with the cam surface 113b. The charge transmission lever 114 has a cam top surface 114c concentric with the center of rotation. The cam top surface 114c is provided so as to be continuous with the cam surface 114b.

A blade locking lever (first locking means) 115 is rotatably attached to the shaft 120 e of the shutter base plate 120 . The blade locking lever 115 is biased clockwise in the front view by a spring (not shown). The blade locking lever 115 has a hook portion 115a, and when the shutter blade group 101 is deployed (the blade lever 102 rotates clockwise in the front view), the hook portion 102d of the blade lever 102 engages the blade. The hook portion 115a of the stop lever 115 is pushed aside and the hook is caught. As a result, the blade lever 102 is locked while the shutter blade group 101 is deployed. The charge transmission lever 114 has a pin portion 114d. When the charge transmission lever 114 is driven by the charge cam 105, the blade locking lever 115 comes into contact with the pin portion 114d and is rotated counterclockwise in the front view to release the lock. .

A blade drive transmission locking lever (second locking means) 117 is rotatably attached to the shaft 120f of the shutter base plate 120 . The blade drive transmission locking lever 117 is urged by a spring (not shown) in the left rotation direction in the front view. The blade drive transmission lever 113 has a lock cam portion 113d, and when driven to rotate counterclockwise in the front view by the biasing force of the spring 116, the blade drive transmission lock lever 117 locks the blade drive transmission lever 113 in the front view. to suppress the movement to the right. The charge transmission lever 114 has an unlocking cam portion 114e. When the charge transmission lever 114 is driven by the charge cam 105 in the left rotation direction in the front view, the blade drive transmission locking lever 117 pushes the blade drive transmission locking lever 117 in the right rotation direction in the front view to lock. Release.

Next, the movement of the shutter device 100 will be described with reference to FIGS. 4 to 6. FIG. 4 is a timing chart showing the operation of the shutter device 100. FIG. FIG. 5 is an explanatory diagram from the standby phase to the photographing phase of the drive unit of the shutter device 100. As shown in FIG. FIG. 6 is an explanatory diagram from the charge phase to the blade return drive phase of the driving section of the shutter device 100. In FIG. FIGS. 5(A)-(D) and FIGS. 6(E)-(H) correspond to states A-H shown in FIG. 4, respectively. 5A' to 5D' and 6E' to 6H' are part of FIGS. 5A to 5D and 6E to 6H, respectively. 1 is a diagram omitting the parts of FIG.

In FIG. 4, state A is a state (standby phase) in which the shutter device 100 is stopped at the photographing standby position, and corresponds to the state shown in FIG. 5A. In the state of FIG. 5A, the shutter blade group 101 is in a superimposed state, and the apertures 120a and 121a are in an opened state. The blade drive transmission lever 113 is urged by a spring 116 so that the cam follower portion 113 a contacts the cam top surface 104 b of the blade drive cam 104 , thereby restricting rotation. The charge transmission lever 114 is urged by a spring 118 so that the cam follower portion 114 a contacts the cam top surface 105 b of the charge cam 105 , thereby restricting the rotation of the charge transmission lever 114 . The drive lever 103 is biased by a main spring 107 so as to come into contact with the surface 102 a of the blade lever 102 .

Blade lever 102 is urged by drive lever 103 and blade urging spring 106 so that cam follower portion 102 b contacts cam top surface 113 c of blade drive transmission lever 113 . Rotation of the blade lever 102 and the drive lever 103 is thereby restricted. At this time, the blade lever 102 overcharges the armature 110 it holds with respect to the yoke 119, and the yoke 119 and the armature 110 are in contact. The blade locking lever 115 is held by the pin portion 114d of the charge transmission lever 114 in the unlocked state (the state rotated counterclockwise in the front view). The blade drive transmission lock lever 117 is held in the unlocked state (the state rotated clockwise in the front view) by the lock release cam portion 114e.

When driving is started from state A shown in FIGS. 4 and 5A, first, by energizing the coil 109 wound around the yoke 119, magnetic force is generated in the yoke 119 and the armature 110 is attracted. Hold. By energizing the motor 108, the blade drive cam 104 and the charge cam 105, which rotate integrally via a gear train (not shown), are rotated. When the charge cam 105 starts to rotate, the cam follower portion 114a of the charge transmission lever 114 separates from the cam top surface 105b of the charge cam 105 that has restricted its rotation. The charge transmission lever 114 is driven counterclockwise in the front view by the biasing force of the spring 118 .

By driving the charge transmission lever 114, the pin portion 114d is separated from the blade locking lever 115, and the blade locking lever 115 becomes ready to lock the blade lever . At the same time, the locking cam portion 113 d is separated from the blade drive transmission locking lever 117 , and the blade drive transmission locking lever 117 becomes ready to lock the blade drive transmission lever 113 .

On the other hand, the cam surface 104a of the blade drive cam 104 is gradually lowered as shown in FIG. Rotate. As the blade drive transmission lever 113 rotates, the cam follower portion 102b of the blade lever 102 is disengaged from the cam surface 113b of the blade drive transmission lever 113 and the blade lever 102 starts rotating. At this time, the drive lever 103 rotates integrally with the blade lever 102 due to the biasing force of the main spring 107 .

State B in FIGS. 4 and 5B is a state in which the blade lever 102 rotates until the amount of overcharge of the yoke 119 of the blade lever 102 becomes zero (travel preparation phase). In this phase, there is no play between blade lever 102 and armature 110, and blade lever 102 and armature 110 collide. In phases prior to this phase, the armature 110 is attracted and held by the yoke 119, thereby restricting the rotation of the blade lever 102 and the drive lever 103, and driving only the blade drive cam 104 and the blade drive transmission lever 113. . At this time, both the cam surface 113b of the blade drive transmission lever 113 and the cam surface 104a of the blade drive cam 104 are sloped, thereby controlling the rotational speed of the blade lever 102 and causing the blade lever 102 and the armature 110 to rotate. It reduces the impact force at the time of collision. As a result, it is possible to prevent unintentional release of adsorption, and to prevent malfunction. In addition, it is possible to reduce the shaking of the shutter blade group 101 held by the blade lever 102, and for fine adjustment of the exposure amount, it is possible to quickly shift to the exposure operation after the shaking of the shutter blade group 101 converges. becomes possible. As a result, it is possible to improve the continuous shooting speed and shorten the release time lag.

In state C of FIGS. 4 and 5C, the blade drive cam 104 rotates while the armature 110 continues to be attracted and held, and the blade drive transmission lever 113 rotates leftward in the front view. This is the state (imaging phase). When the blade drive cam 104 and the charge cam 105 rotate to this phase, the energization of the motor 108 is stopped. When the power supply to the coil 109 is stopped after the power supply to the motor 108 is stopped, the magnetic force of the armature 110 is released, and the driving lever 103 and the blade lever 102 are rotated clockwise in the front view by the biasing force of the main spring 107. to start rotating. As the blade lever 102 rotates, the shutter blade group 101 is expanded to block the light beams passing through the apertures 120a and 121a. By controlling the reset operation of the image sensor 7 and the expansion operation of the shutter blade group 101, it is possible to control the exposure amount of the image sensor 7 (perform the exposure operation).

Here, when the blade drive transmission lever 113 rotates in the left rotation direction in the front view, the blade drive transmission lock lever 117 rotates in the left rotation direction in the front view due to the bias of a spring (not shown). , abut against the locking cam portion 113 d of the blade drive transmission lever 113 . As a result, the bouncing of the blade drive transmission lever 113 (rotation in the right rotation direction in the front view) can be suppressed. If the blade drive transmission lever 113 exists within the operation range of the blade lever 102, the blade drive transmission lever 113 collides with the blade lever 102, and the exposure amount of the imaging sensor 7 cannot be controlled accurately. Therefore, it is necessary to stop the bouncing of the blade drive transmission lever 113 before the shutter blade group 101 starts to expand. In this embodiment, by providing the blade drive transmission locking lever 117, it is possible to shorten the release time lag and improve the continuous shooting speed.

State D in FIGS. 4 and 5D is a state (photographing phase) in which the exposure amount control (expanding operation of the shutter blade group 101 and rotation of the blade lever 102 in the right rotation direction in the front view) is completed. The hook portion 102d of the blade lever 102 pushes aside the hook portion 115a of the blade locking lever 115 before the blade lever 102 is completely turned in the right direction in the front view, and the hook portion 115a of the blade locking lever 115 is engaged and locked. If the shutter blade group 101 is greatly bounded (rotated in the overlapping direction) after being in the unfolded state, there is a possibility that the apertures 120a and 121a that were once completely shielded from light will open again. Therefore, by restricting the movement of the blade lever 102 with the blade locking lever 115, the bounding of the shutter blade group 101 can be suppressed. As a result, it is possible to prevent the exposure amount from fluctuating due to unintended re-exposure.

State E in FIGS. 4 and 6E is a state (charging phase) during which the main spring 107 is being charged (the drive lever 103 is rotated counterclockwise in the front view). After the exposure amount control is completed by the reset operation of the imaging sensor 7 and the expansion operation of the shutter blade group 101, an electric circuit (not shown) reads out the exposure information from the imaging sensor 7, and at the same time the motor 108 is energized to operate the blade drive cam 104. And the drive of the charge cam 105 is started. When the charge cam 105 rotates, the cam surface 105a contacts the cam follower portion 114a of the charge transmission lever 114 to rotate the charge transmission lever 114 against the biasing force of the spring 118. As shown in FIG. When the charge transmission lever 114 starts to rotate, the cam surface 114b contacts the cam follower portion 103b of the drive lever 103 and charges the main spring 107 via the drive lever 103. As shown in FIG.

At this time, the driving angle of the driving lever 103 is approximately 90 degrees, which is very large. Therefore, in order to directly drive the drive lever 103 with the charge cam 105 provided on the same surface of the shutter base plate 120, the cam follower portion 103b of the drive lever 103 should be charged such that it once approaches the center of rotation of the charge cam 105 and then moves away. need to do When performing such charging, it is difficult to smooth the load, and a motor 108 capable of outputting a large torque is required. In this embodiment, the drive is performed via a charge transmission lever 114 configured such that the contact point with the charge cam 105 is shorter than the contact point with the drive lever 103 from the center of rotation. With such a configuration, the cam surface 105a of the charge cam 105 can be used in one direction from the rotation center to the outside, and the load can be smoothed like a normal cam. As a result, a small, low-cost, low-torque motor 108 can be employed.

State F in FIGS. 4 and 6F is a state (transfer waiting phase) in which charging of the main spring 107 (rotation of the drive lever 103 to the left in the front view) is completed. When the charge cam 105 continues to be driven from the state E phase (charge phase), the cam follower portion 103b of the drive lever 103 contacts the cam top surface 114c of the charge transmission lever 114, and the drive lever 103 stops rotating. Then, the cam follower portion 114a of the charge transmission lever 114 comes into contact with the cam top surface 105b of the charge cam 105, and the rotation of the charge transmission lever 114 stops. As a result, the stop position of the drive lever 103 is not affected by the shape error of the charge cam 105 . As a result, the stop position of the drive lever 103 can be stabilized.

The charge transmission lever 114 rotates in the left rotation direction in the front view, and the lock release cam portion 114e rotates the blade drive transmission locking lever 117 in the right rotation direction in the front view. The blade drive transmission lever 113 is turned to the right in the front view). Then, the charge transmission lever 114 rotates the blade locking lever 115 leftward in the front view by the pin portion 114d, thereby releasing the locked state (the blade lever 102 can be rotated leftward in the front view). state). When driving is performed up to the phase of state F (transfer waiting phase), the power supply to the motor 108 is stopped, and the driving of the blade drive cam 104 and the charge cam 105 is stopped.

If the apertures 120a and 121a are opened while the exposure information is being read from the imaging sensor 7, there is a possibility that the light beams passing through the apertures 120a and 121a become noise. In order to prevent such noise, it is necessary to stop the shutter device 100 in the state F phase (transfer waiting phase) while the exposure information is being read from the imaging sensor 7 and keep the shutter blade group 101 in the unfolded state. be.

After the reading of the exposure information is completed, in preparation for the next photographing, the motor 108 is energized again to open the apertures 120a and 121a to open the shutter blade group 101 and the blade drive cam 104. Drive the charge cam 105 . When the blade drive cam 104 rotates to the left in the front view, the cam surface 104a comes into contact with the cam follower portion 113a of the blade drive transmission lever 113, causing the blade drive transmission lever 113 to move against the biasing force of the spring 116. Rotate to the right in the front view. As the blade drive transmission lever 113 continues to rotate, the cam surface 113b comes into contact with the cam follower portion 102b of the blade lever 102, causing the blade lever 102 to rotate counterclockwise in the front view against the biasing force of the blade biasing spring 106. direction.

State G in FIGS. 4 and 6G is a state (blade return driving phase) while the blade lever 102 is rotating. As shown in FIG. 6(G′), the cam surface 113b of the blade drive transmission lever 113 is configured to switch after the phase of state G (blade return drive phase). The rotation speed of 102 slows down. As the rotation continues, the surface 102a of the blade lever 102 comes into contact with the drive lever 103 as shown in FIGS. 4 and 6(H). As the driving continues, the yoke 119 and the armature 110 come into contact with each other. In this way, by reducing the rotation speed of the blade lever 102 before the blade lever 102 and the drive lever 103 come into contact with each other, the collision between the blade lever 102 and the drive lever 103 is softened, and the behavior is stable and durable. It is possible to improve the quality.

Here, the blade lever 102 is driven against the biasing force of the main spring 107 that generates a strong biasing force after coming into contact with the drive lever 103, so that it is possible to further decelerate. With such a configuration, the rotation speed at the timing of contact between the yoke 119 and the armature 110 can be further reduced. Therefore, in addition to the improvement in durability, the stability of behavior such as vibration of the shutter blade group 101 shortens the time until the start of the next photographing operation, thereby improving the continuous shooting speed. In this embodiment, the rotational speed of the blade lever 102 is decelerated at a clear inflection point. 113b may be configured.

As the drive continues, the yoke 119 and the armature 110 are overcharged, and the cam follower portion 102b of the blade lever 102 comes into contact with the cam top surface 113c of the blade drive transmission lever 113. The cam follower portion 113 a of the blade drive transmission lever 113 contacts the cam top surface 104 b of the blade drive cam 104 . As a result, the stop position of the blade lever 102 is not affected by the shape error of the blade drive cam 104, so the stop position of the blade lever 102 can be stabilized.

After the cam follower portion 113a of the blade drive transmission lever 113 comes into contact with the cam top surface 104b of the blade drive cam 104, the energization of the motor 108 is stopped. Stop at the indicated phase (wait phase). As described above, a series of operations from state A through state H to return to state A are operations required for one photographing by the shutter device 100 of the present embodiment.

As described above, in this embodiment, the superimposition operation of the shutter blade group 101 (the operation of rotating the blade lever 102 in the left rotation direction in the front view) for photographing preparation is performed by the output of the motor 108 . Therefore, the urging directions of the main spring 107 and the blade urging spring 106 can be aligned in the right rotation direction in the front view. In addition, in the configuration of the present embodiment, the combined biasing force of the main spring 107 and the blade biasing spring 106 acts on the blade lever 102 that deploys the shutter blade group 101 when controlling the exposure amount. It becomes possible to reduce the biasing force of the spring 107 . The motor 108 is required to produce maximum output during the charging operation of the main spring 107 . Therefore, by reducing the biasing force of the main spring 107, it is possible to use a smaller, lighter, and less expensive low-torque motor 108. FIG.

As described above, in this embodiment, the shutter device 100 includes the shutter blade group 101, the first driving means, the second driving means, the first biasing means, the second biasing means, the third driving means, and a fourth driving means. The shutter blade group can reciprocate between a closed state (unfolded state) for closing the opening and an open state (overlapping state) for opening the opening. The first driving means (blade lever 102) is connected to the shutter blade group. The second driving means (driving lever 103) drives the first driving means in the first direction (clockwise rotation direction, development direction) in which the shutter blade group closes the opening. A first biasing means (blade biasing spring 106) biases the first driving means in a first direction. A second biasing means (main spring 107) biases the second driving means in the first direction. The third drive means (blade drive cam) drives the first drive means in the second direction (counterclockwise rotation direction, overlapping direction) in which the shutter blade group opens the aperture. A fourth drive means (charge cam 105) drives the second drive means in the second direction.

Preferably, the shutter device has a motor 108 driving the third drive means and the fourth drive means. Also preferably, the shutter device has a yoke 119 and a coil 109 wrapped around the yoke. The yoke can attract and hold the armature 110 of the first driving means by energizing the coil. Preferably, when the third driving means drives the first driving means, the first driving means and the second driving means contact each other after the first driving means decelerates, and the first driving means Contact between the armature and the yoke follows contact between the means and the second drive means.

In this embodiment, the shutter device has first power transmission means (blade drive transmission lever 113) and second power transmission means (charge transmission lever 114). The first power transmission means transmits power of the third drive means to the first drive means. The second power transmission means transmits the power of the fourth drive means to the second drive means.

Preferably, the shutter device has first locking means (blade locking lever 115) for locking the first driving means while the first driving means is driven by the second driving means. More preferably, locking of the first driving means by the first locking means is released by the fourth driving means driving the second power transmission means.

Preferably, the shutter device has a third biasing means (spring 116) and a second locking means (blade drive transmission locking lever 117). The third biasing means biases the first power transmission means. The second locking means locks the first power transmission means while the first power transmission means is driven by the biasing force of the third biasing means. More preferably, locking of the first power transmission means by the second locking means is released by the fourth driving means driving the second power transmission means.

The shutter device of this embodiment can be driven by a low-torque motor. Therefore, according to this embodiment, it is possible to provide a shutter device and an imaging device that can be made smaller and less expensive.

Although preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist.

100 shutter device 101 shutter blade group 102 blade lever (first driving means)
103 drive lever (second drive means)
104 blade drive cam (third drive means)
105 charge cam (fourth driving means)
106 blade biasing spring (first biasing means)
107 main spring (second biasing means)

Claims (7)

a shutter blade group capable of reciprocating between a closed state for closing the opening and an open state for opening the opening;
a first driving means connected to the shutter blade group;
a second driving means for driving the first driving means in a first direction in which the shutter blade group closes the opening;
a first biasing means for biasing the first driving means;
a second biasing means for biasing the second driving means in the first direction;
a third driving means for driving the first driving means;
a first power transmission means for transmitting power of the third drive means to the first drive means;
a fourth drive means for driving the second drive means in a second direction in which the shutter blade group opens the aperture;
a second power transmission means for transmitting the power of the fourth drive means to the second drive means ,
The fourth driving means is configured such that the distance from the center of rotation is shorter at the point of contact with the fourth driving means than at the point of contact with the second driving means. A shutter device , wherein the second drive means is driven via a power transmission means . the first biasing means biases the first driving means in the first direction;
2. A shutter device according to claim 1 , wherein said third driving means drives said first driving means in said second direction. 3. The apparatus according to claim 1 , further comprising first locking means for locking said first driving means while said first driving means is driven by said second driving means. shutter device. 4. Locking of said first driving means by said first locking means is released when said fourth driving means drives said second power transmission means. Shutter device as described. a third biasing means for biasing the first power transmission means;
and second locking means for locking the first power transmission means in a state where the first power transmission means is driven by the biasing force of the third biasing means. The shutter device according to any one of claims 1 to 4 . 5. Locking of said first power transmission means by said second locking means is released when said fourth driving means drives said second power transmission means. Shutter device according to. A shutter device according to any one of claims 1 to 6 ;
and an imaging device that photoelectrically converts an optical image formed via an imaging optical system.

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